AFP Detective Superintendent Ian Bate says police are still investigating the operation, but it is clear they were managing the women when they were not licensed to do so.

"They were providing a number of brothels with these sex workers," he said.

"They were taking money in relation to the services provided and they were indeed rostering the women, placing them in the different brothels, providing accommodation, charging them for it, providing them other services such as taxi fares and charging them for it."

Detective Superintendent Rod Jouning from Victoria Police believes the exploitation of sex workers is not common.

"It's our view that it's not a large issue but the exploitation of women in any sense is intolerable," he said.

Dr Caroline Norma, an academic from RMIT who researches the Victorian sex industry, believes the problem is entrenched saying there is a standard business model.

"These women come into Australia and get placed into these illegal brothels and then over time, once they've been had prostitution done to them in these venues and the pimps and the businessmen have made money off them, then they're moved into, through networks of the legal brothels," she said.

"But they're moved into these legal brothels on a subcontracted basis."

Dr Norma says this case shows that the regulation of the sex industry, which was supposed to protect women, is not working.

"The regulation is entirely about protecting the public and protecting the customs or the sex industries, not about protecting the women in the industry," she said.